Freeze-fracture replication of junctional complexes in unincubated and incubated chick embryos

@article{Bellairs2004FreezefractureRO,
  title={Freeze-fracture replication of junctional complexes in unincubated and incubated chick embryos},
  author={Ruth Bellairs and A. S. Breathnach and M. Gross},
  journal={Cell and Tissue Research},
  year={2004},
  volume={162},
  pages={235-252}
}
SummaryJunctional complexes have been investigated in the epiblast of young chick embryos by examination of freeze-fracture replicas and of sections of comparable specimens stained with lanthanum nitrate. By means of freeze-fracture, tight junctions were shown to be present in the unincubated embryo (stage 1 of Hamburger and Hamilton). The number of ridges or grooves was found to vary between 2 and 10 near the dorsal border, whereas isolated ridges were found more ventrally. Lanthanum was… 

Cell junctions in explanted tissues from early chick embryos

It is suggested that the differences between the two types of tissue may be related to cell cohesiveness, which appears to be relatively low in the hypoblast and high in the definitive endoblast.

An electron-microscopical analysis of embryonic chick tissues explanted in culture

Differences in cell/substrate and cell/cell morphology are discussed in relation to the different behavioural characteristics of the three tissues.

Communication compartments in the axial mesoderm of the chick embryo

The results indicate that dye-coupling becomes restricted in a spatial and temporal manner as the mesodermal cells mature, and some compartments also have borders similar to those described by cell lineage studies.

Ultrastructural details of Sertoli cell junctional complexes in vivo and their modifications in tissue culture

The Sertoli cell contact specializations show a progressive disorganization in vitro correlated with the duration of the period in culture, and the presence of a new type of membrane specialization has been revealed.

Mechanisms, mechanics and function of epithelial–mesenchymal transitions in early development

Biomechanical regulation of EMT and epithelial morphogenesis in amniote epiblast

This review is aimed at providing a background based on which epiblast morphogenesis, including its transition between the epithelial and mesenchymal states, can be understood from a biomechanical perspective, leading to a better understanding of biomechanicals logics and constraints governing multicellular organization.

Epithelial monolayer development and tight junction assembly on nanopillar arrays

It is shown that conditions can be defined to allow growth of mature, correctly assembled epithelial monolayers with nanopillars localized to lateral intercellular spaces, which sets the stage for application of nanotechnologies for perturbation and analysis of epithelial biology.

Connecting cords and morphogenetic movements in the quail blastoderm

Connecting cords are elongated telophase bridges persisting between separating daughter cells in the upper cell layer of the quail blastoderm where a high mitotic activity accompanied by interkinetic nuclear migration coincides with morphogenetic movements.

Strong electrical currents leave the primitive streak of chick embryos.

The electrical fields above chick embryos were explored with a vibrating probe. These fields indicate that steady currents with exit densities of the order of 100 microamperes per square centimeter

A cascade of molecular events during neural induction

It is demonstrated that FGF signalling makes a major contribution to the onset of neural induction by inducing transcription factors and chromatin modifiers, providing further evidence that neural induction begins before gastrulation.

References

SHOWING 1-10 OF 38 REFERENCES

Junctional complexes in the preimplantation rabbit embryo

These experiments showed that although rudimentary junctions were present between blastomeres of the early cleavage stages, effective tight junications were not present until the blastocyst stage, and this form of gap junction was not demonstrated.

Intercellular contact in the unincubated chick embryo

  • E. Sanders
  • Biology
    Zeitschrift für Zellforschung und Mikroskopische Anatomie
  • 2004
SummaryThe unincubated chick blastoderm, which consists of a complete upper epithelial layer of one cell thickness (epiblast) and an incomplete lower layer (hypoblast), was examined with the electron

ASSEMBLY OF GAP JUNCTIONS DURING AMPHIBIAN NEURULATION

The assembly process in both apical and basal regions conforms with the concept of translational movement of particles within a fluid plasma membrane.

Further observations on the fine structure of freeze-cleaved tight junctions.

Evidence is presented suggesting that fragments of tight junctions can be internalized and broken down in lysosome-like vesicles.

VARIATIONS IN TIGHT AND GAP JUNCTIONS IN MAMMALIAN TISSUES

The fine structure and distribution of tight and gap junctions in epithelia of the rat pancreas, liver, adrenal cortex, epididymis, and duodenum, and in smooth muscle were examined in paraformaldehyde-glutaraldehyde-fixed, tracer-permeated, and freeze-fractured tissue preparations.

DIFFERENTIATION OF THE JUNCTIONAL COMPLEX OF SURFACE CELLS IN THE DEVELOPING FUNDULUS BLASTODERM

The structure of the junctional complex between surface cells was investigated in blastula, mid gastrula, late gastrulas, and early embryo of the teleost fish Fundulus heteroclitus to find that desmosomes and their associated system of filaments are well developed.

Gap junctions between electrotonically coupled cells in tissue culture and in brown fat.

An electron microscopic study of replicas of frozen-fractured BHK21 cells and brown fat cells of newborn mice indicates that gap junctions, when they are the only intercellular junctions present, are sufficient to account for electronic coupling between cells.